From c8ab4bae5895bb88dd0fe0432219826d6b127dbf Mon Sep 17 00:00:00 2001 From: "Isaac J. Manjarres" Date: Thu, 7 Jan 2021 23:01:19 -0800 Subject: [PATCH] FROMLIST: iommu: Introduce map_sg() as an IOMMU op for IOMMU drivers Add support for IOMMU drivers to have their own map_sg() callbacks. This completes the path for having iommu_map_sg() invoke an IOMMU driver's map_sg() callback, which can then invoke the io-pgtable map_sg() callback with the entire scatter-gather list, so that it can be processed entirely in the io-pgtable layer. For IOMMU drivers that do not provide a callback, the default implementation of iterating through the scatter-gather list, while calling iommu_map() will be used. Bug: 176779203 Link: https://lore.kernel.org/linux-iommu/1610376862-927-1-git-send-email-isaacm@codeaurora.org/T/#t Change-Id: I3d5a8a9e8648649d8dcdda3fa1df41d72f87a528 Signed-off-by: Isaac J. Manjarres Tested-by: Sai Prakash Ranjan --- drivers/iommu/iommu.c | 13 +++++++++++++ include/linux/iommu.h | 5 +++++ 2 files changed, 18 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 0f4dc25d46c9..edaa7979433c 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2516,11 +2516,24 @@ static size_t __iommu_map_sg(struct iommu_domain *domain, unsigned long iova, struct scatterlist *sg, unsigned int nents, int prot, gfp_t gfp) { + const struct iommu_ops *ops = domain->ops; size_t len = 0, mapped = 0; phys_addr_t start; unsigned int i = 0; int ret; + if (ops->map_sg) { + ret = ops->map_sg(domain, iova, sg, nents, prot, gfp, &mapped); + + if (ops->iotlb_sync_map) + ops->iotlb_sync_map(domain); + + if (ret) + goto out_err; + + return mapped; + } + while (i <= nents) { phys_addr_t s_phys = sg_phys(sg); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index b95a6f8db6ff..e744eaad8da6 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -190,6 +190,8 @@ struct iommu_iotlb_gather { * @attach_dev: attach device to an iommu domain * @detach_dev: detach device from an iommu domain * @map: map a physically contiguous memory region to an iommu domain + * @map_sg: map a scatter-gather list of physically contiguous chunks to + * an iommu domain. * @unmap: unmap a physically contiguous memory region from an iommu domain * @flush_iotlb_all: Synchronously flush all hardware TLBs for this domain * @iotlb_sync_map: Sync mappings created recently using @map to the hardware @@ -241,6 +243,9 @@ struct iommu_ops { void (*detach_dev)(struct iommu_domain *domain, struct device *dev); int (*map)(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot, gfp_t gfp); + int (*map_sg)(struct iommu_domain *domain, unsigned long iova, + struct scatterlist *sg, unsigned int nents, int prot, + gfp_t gfp, size_t *mapped); size_t (*unmap)(struct iommu_domain *domain, unsigned long iova, size_t size, struct iommu_iotlb_gather *iotlb_gather); void (*flush_iotlb_all)(struct iommu_domain *domain);